(!!!) (Recommended Pair) 6EM7 Sylvania NOS black plates 1960's (1.5ma/1.7ma and 46ma/51ma)
(!!!) 6EA7 Tungsol NOS 1960's (1.8ma/64ma) (strong single)
(!!) (Recommended Single) 6EM7 Continental Westinghouse Canada NOS 1960's (1.7ma/52ma)
(!!) 6EA7=6EM7 Sylvania Zenith coin-base NOS 1970's (1.8/65ma)
6EA7 GE USA black base rebranded Zenith 1960 used/good (3.6ma/35ma)
6EM7 GE NOS 1963 (1.6ma/48ma)
6EM7 RCA black plates NOS 1960 (1.9ma and 45.4ma)
6EM7 RCA coin-base black plates NOS 1970's broken guide pin (2.4ma/50ma)
6EM7 RCA coin-base black plates used/good 1970's (2.6ma/63ma)
6EM7 RCA coin-base NOS 1972 (2.7ma/58ma)
6EM7 RCA coin-base used (2.5ma/28ma)
6EM7 Sylvania coin-base NOS 1970's (1.0ma/42ma)
6EM7 Westinghouse NOS 1965 (1.5ma/52ma)
